Ning Lan

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Verified

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• Ph.D.
• Professor at University of Illinois Chicago

Current bionic hands lack the ability of fine force manipulation for grasping fragile objects due to missing human neuromuscular compliance in control. This incompatibility between prosthetic devices and the sensorimotor system has resulted in a high abandonment rate of hand prostheses. To tackle this challenge, we employed a neuromorphic modeling...

Current bionic hands lack the ability of fine force manipulation for grasping fragile objects due to missing human neuromuscular compliance in control. This incompatibility between prosthetic devices and the sensorimotor system has resulted in a high abandonment rate of hand prostheses. To tackle this challenge, we employed a neuromorphic modeling...

This study develops biomimetic strategies for slip prevention in prosthetic hand grasps. The biomimetic system is driven by a novel slip sensor, followed by slip perception and preventive control. Here, we show that biologically inspired sensorimotor pathways can be restored between the prosthetic hand and users. A Ruffini endings-like slip sensor...

The ability of a novel biorealistic hand prosthesis for grasp force control reveals improved neural compatibility between the human-prosthetic interaction. The primary purpose here was to validate a virtual training platform for amputee subjects and evaluate the respective roles of visual and tactile information in fundamental force control tasks....

Sensory feedback provides critical interactive information for the effective use of hand prostheses. Non-invasive neural interfaces allow convenient access to the sensory system, but they communicate a limited amount of sensory information. This study examined a novel approach that leverages a direct and natural sensory afferent pathway, and enable...

Background Advanced prosthetic hands may embed nanosensors and microelectronics in their cosmetic skin. Heat influx may cause damage to these delicate structures. Protecting the integrity of the prosthetic hand becomes critical and necessary to ensure sustainable function. This study aims to mimic the sensorimotor control strategy of the human hand...

Introduction Either non-invasive somatotopic or substitute sensory feedback is capable of conveying a single modality of sensory information from prosthetic hands to amputees. However, the neurocognitive ability of amputees to integrate multi-modality sensory information for functional discrimination is unclear. The purpose of this study was to ass...

Significant advances have been made to improve control and to provide sensory functions for bionic hands. However, great challenges remain, limiting wide acceptance of bionic hands due to inadequate bidirectional neural compatibility with human users. Recent research has brought to light the necessity for matching neuromechanical behaviors between...

Object: Based on the comparisons of the somatosensory event-related potentials (ERPs), the object of this study is to investigate the underlying cognition mechanism of somatotopy and the homology of tactile sensation between the projected fingers in the residual limb and the natural fingers in the intact limb. Methods: One amputee subject and th...

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective : Human neuromuscular reflex control provides a biological model for a compliant hand prosthesis. Here we present a computational approach to understanding the emerging human-like compliance, force and position control, and stiffness adaptati...

In this paper, a novel prototype of a cable-driven prosthetic hand with biorealisitic muscle property was developed. A pair of antagonistic muscles controlled the flexion and extension of the prosthetic index finger. Biorealistic properties of muscle were emulated using a neuromorphic model of muscle reflex in real time. The model output was couple...

The absence of somatotopic sensory feedback limits the function of conventional prosthetic hands. In this study, we integrated a non-invasive sensory feedback system into a commercial Bebionic hand with new customized surface stimulation electrodes. Multiple modalities of tactile and hand aperture sensory information were conveyed to the amputee vi...

Tremor in Parkinson's disease (PD) is caused by synchronized activation bursts in limb muscles. Deep Brain Stimulation (DBS) is an effective clinical therapy for inhibiting tremor and improving movement disorders in PD patients. However, the neural mechanism of how tremor symptom is suppressed by DBS at motor unit (MU) level remains unclear. This p...

A previous study indicated that synergy-based functional electrical stimulation (FES) may improve instantaneous upper-limb motor performance for stroke survivors. However, it remains unclear whether the improvements will sustain over time to achieve functional gains associated with a task-oriented training (TOT). This pilot study was designed to in...

Objective. Evoked tactile sensation (ETS) elicited by transcutaneous electrical nerve stimulation (TENS) is promising to convey digit-specific sensory information to amputees naturally and non-invasively. Fitting ETS-based sensory feedback to amputees entails customizing coding of multiple sensory information for each stimulation site. This study w...

The human hand has compliant properties arising from muscle biomechanics and neural reflexes, which are absent in conventional prosthetic hands. We recently proved the feasibility to restore neuromuscular reflex control (NRC) to prosthetic hands using real-time computing neuromorphic chips. Here we show that restored NRC augments the ability of ind...

Model-based biomimetic control with neuro-muscular reflex requires accurate representation of muscle fascicle length, which affects both force generation capability of muscle and dynamics of muscle spindle. However, physiological data are insufficient to guide the selection of range of fascicle length for task control. Here a reverse engineering ap...

Restoring neuromuscular reflex properties in the control of a prosthetic hand may potentially approach human-level grasp functions in the prosthetic hand. Previous studies have confirmed the feasibility of real-time emulation of a monosynaptic spinal reflex loop for prosthetic control [1]. This study continues to explore how well the biomimetic con...

The ability to perceive prosthetic grasping may enable amputees to better interact with external objects. This may require customized coding of multiple sensory feedback for each amputee. This study developed a protocol to determine optimal modulation ranges of sensations elicited by transcutaneous electrical nerve stimulation (TENS). These sensati...

The ability to perceive prosthetic grasping may enable amputees to better interact with external objects. This may require customized coding of multiple sensory feedback for each amputee. This study developed a protocol to determine optimal modulation ranges of sensations elicited by transcutaneous electrical nerve stimulation (TENS). These sensati...

Integrating a prosthetic hand to amputees with seamless neural compatibility presents a grand challenge to neuroscientists and neural engineers for more than half century. Mimicking anatomical structure or appearance of human hand does not lead to improved neural connectivity to the sensorimotor system of amputees. The functions of modern prostheti...

Background: This paper describes the design and test of an automated functional electrical stimulation (FES) system for poststroke rehabilitation training. The aim of automated FES is to synchronize electrically induced movements to assist residual movements of patients. Methods: In the design of the FES system, an accelerometry module detected...

Biomimetic flexible tactile sensors endow prosthetics with the ability to manipulate objects, similar to human hands. However, it is still a great challenge to selectively respond to static and sliding friction forces, which is crucial tactile information relevant to the perception of weight and slippage during grasps. Here, inspired by the structu...

Current control of prosthetic hands is ineffective when grasping deformable, irregular, or heavy objects. In humans, grasping is achieved under spinal reflexive control of the musculotendon skeletal structure, which produces a hand stiffness commensurate with the task. We hypothesize that mimicking reflex on a prosthetic hand may improve grasping p...

The objective of this study is to develop an experimental protocol to define the range of modulation for different sensory modalities elicited by transcutaneous electrical nerve stimulation (TENS) in amputees with evoked tactile sensation (ETS). Modulation ranges of sensory modalities, such as vibration, buzz, tingling etc., are essential for desig...

This study assessed the feasibility to restore finger-specific sensory feedback in transradial amputees with electrical stimulation of evoked tactile sensation (ETS). Here we investigated primary somatosensory cortical (SI) responses of ETS using Magnetoencephalography. SI activations revealed a causal correlation with peripheral stimulation of pro...

Prosthetic and therapeutic devices have been developed to ameliorate the quality of daily living for people with amputation or neurological disorders. However, many of them fall short of functional benefits, and therefore, are frequently rejected by users due to awkward control, or no awareness of interaction during tasks. Traditional wisdom in the...

Objective. Resting tremor may compound the effects of bradykinesia to further prolong the initiation of voluntary movement in patients with Parkinson’s disease (PD). However, the interaction between resting tremor and voluntary movements in these PD patients has not been well understood. Recently, we demonstrated that cutaneous afferents evoked by...

Background A large population of patients with Parkinson’s disease (PD) displays the symptom of resting tremor. However, the extent that resting tremor may affect the performance of movement control has not been evaluated specifically. This study aims at establishing methods to quantitatively evaluate motor performance in PD patients with tremor, a...

Functional Electrical Stimulation (FES) provides a promising technology for rehabilitation of upper-limb motor functions following stroke. It enables activation of individual muscles to assist restoration of impaired muscle synergies toward normal patterns. However, there lacks a systematic approach to optimize the FES stimulation patterns delivere...

Evoked tactile sensation (ETS) is induced with stimulation of areas in the projected finger map (PFM) in the stump skin of forearm amputees. The aim of the present study is to further explore the neural correlation of the ETS with central activities in the somatosensory cortex (SI). Two forearm amputees were recruited to participate in this study....

Introduction/Background The objective of this study is to test the clinical effectiveness of a synergy-based multi-muscle functional electrical stimulation (FES) strategy to accelerate post-stroke motor function recovery via a new task-oriented training protocol. Material and method A randomized, single-blind, placebo controlled protocol was desig...

Essential tremor, also referred to as familial tremor, is an autosomal dominant genetic disease and the most common movement disorder. It typically involves a postural and motor tremor of the hands, head or other part of the body. Essential tremor is driven by a central oscillation signal in the brain. However, the corticospinal mechanisms involved...

The central nervous system produces movements by activating specifically programmed muscle synergies that are also altered with injuries in the brain, such as stroke. In this study, we hypothesize that there exists a positive correlation between task-specific muscle synergy and motor functions at joint and task levels in patients following stroke....

Background Recent study suggests that tremor signals are transmitted by way of multi-synaptic corticospinal pathway. Neurophysiological studies have also demonstrated that cutaneous afferents exert potent inhibition to descending motor commands by way of spinal interneurons. We hypothesize in this study that cutaneous afferents could also affect th...

Evidence suggests that humans tune their motor behavior in response to environmental uncertainty. Such risk-aware sensorimotor performance is hypothetically affected in stroke due to impaired sensorimotor control, but its existence and the detailed pattern of impairment remain unclear - particularly due to lack of approaches for measurement of dyna...

There exists a gap from experimental data to the understanding of neural control of movements. This research topic was dedicated to promote computational modeling approach that can facilitate data interpretation (Niu et al.; Ranjbaran and Galiana; Pearson et al.; Sharif Razavian et al.; Malik et al.), elucidate control theories (Ueyama; Ota et al.;...

Muscle synergy represents a central neural module that organizes and activates a group of muscles when performing a certain task. However, whether muscle synergy is a good physiological indicator of motor ability in task performance for patients suffering stroke is not clear. The purpose of this study is to understand how information of task-specif...

More than 70% of patients suffering Parkinson's disease (PD) exhibit resting tremor in their extremities, hampering their ability to perform daily activities. Based on our earlier studies on corticospinal transmission of tremor signals [10,11], we hypothesize that cutaneous afferents evoked by surface stimulation can produce an inhibitory effect on...

Neuromuscular electrical stimulation (NMES) is a promising assistive technology for stroke rehabilitation. Here we present the design and development of a multimuscle stimulation system as an emerging therapy for people with paretic stroke. A network-based multichannel NMES system was integrated based on dual bus architecture of communication and a...

Involuntary central oscillations at single and double tremor frequencies drive the peripheral neuromechanical system of muscles and joints to cause tremor in Parkinson’s disease (PD). The central signal of double tremor frequency was found to correlate more directly to individual muscle EMGs (Timmermann et al. 2003). This study is aimed at investig...

Mounting evidence suggests that both α and γ motoneurons are active during movement and posture, but how does the central motor system coordinate the α-γ controls in these tasks remains sketchy due to lack of in vivo data. Here a computational model of α-γ control of muscles and spindles was used to investigate α-γ integration and coordination for...

Objective. The goal of this study is to characterize the phenomenon of evoked tactile sensation (ETS) on the stump skin of forearm amputees using transcutaneous electrical nerve stimulation (TENS). Approach. We identified the projected finger map (PFM) of ETS on the stump skin in 11 forearm amputees, and compared perceptual attributes of the ETS in...

Tactile sensory feedback plays a key role in accomplishing the dexterous manipulation of prosthetic hands for the amputees, and the non-invasive transcutaneous electrical nerve stimulation (TENS) of the phantom finger perception (PFP) area would be an effective way to realize sensory feedback clinically. In order to realize the high-spatial-resolut...

The lack of reliable sensory feedback has been one of the barriers in prosthetic hand development. Restoring sensory function from prosthetic hand to amputee remains a great challenge to neural engineering. In this paper, we present the development of a sensory feedback system based on the phenomenon of evoked tactile sensation (ETS) at the stump s...

Recent experiments have suggested that the central nervous system (CNS) makes use of muscle synergies as a neural strategy to simplify the control of a variety of movements by using a single pattern of neural command signal. This nature of muscle coordination could have great significance in the treatment and rehabilitation of upper limb impairment...

Loss of sensory function for upper-limb amputees inevitably devastates their life qualities, and lack of reliable sensory feedback is the biggest defect to sophisticated prosthetic hands, greatly hindering their usefulness and perceptual embodiment. Thus, it is extremely necessary to accomplish an intelligent prosthetic hand with effective tactile...

It is widely assumed that neural control of movement is carried out by the a motor system sufficiently. The role of the γ motor system in movement and posture has not been adequately addressed in motor control studies. Here, we propose a modular control model for movement and posture based on propriospinal neuronal (PN) network and spinal α-γ motor...

Cortical oscillatory signals of single and double tremor frequencies act together to cause tremor in the peripheral limbs of patients with Parkinson's disease (PD). But the corticospinal pathway that transmits the tremor signals has not been clarified, and how alternating bursts of antagonistic muscle activations are generated from the cortical osc...

It has been hypothesized that propriospinal neurons (PNs) in the C3-C4 spinal cord mediates cortical motor commands to the peripheral muscles during tremor in patients with Parkinson's disease (PD). However, there has been no direct evidence so far to support the role of PN in transmitting tremor commands. In this paper, we report the positive corr...

This paper reports a pilot study to explore the plausibility of using the phenomenon of phantom finger perception (PFP) in amputees to develop sensory feedback for prosthetic hand. PFP can be aroused by touching a specific part of the skin in the stump area of amputees. We hypothesized that transcutaneous electrical stimulation (TES) can evoke the...

In this paper, a novel experimental method was developed to study planar arm movement control in tremor dominant Parkinson's (PD) patients. The method utilized a ball-bearing supported fiberglass brace apparatus against gravity to maintain the upper extremity in the horizontal plane. Subjects can perform postural and movement tasks with minimum dam...

The future development of artificial limb is to provide sensory feedback for amputee users. Cutaneous electrical stimulation is a convenient and energy efficient way to produce substituted sensory information. In this paper, we present the results of psychophysical experiments of electrotactile stimulation in normal human subjects. The purposes of...

The purpose of this study is to validate a neuromechanical model of the virtual arm (VA) by comparing emerging behaviors of the model to those of experimental observations. Hand stiffness of the VA model was obtained by either theoretical computation, or simulated perturbations. Variability in hand position of the VA was generated by adding signal...

Background: Neurogenic bladder associated with spinal cord injury (SCI) often results in serious disruption of lower urinary tract function. Compared to conventional therapies, sacral neuromodulation (SNM) may offer an alternative, non-destructive treatment for SCI patients with bladder dysfunction. Understanding bladder reflex changes following S...

Proprioceptive afferents from muscle spindles encode information about peripheral joint movements for the central nervous system (CNS). The sensitivity of muscle spindle is nonlinearly dependent on the activation of gamma (γ) motoneurons in the spinal cord that receives inputs from the motor cortex. How fusimotor control of spindle sensitivity affe...

It has been shown that normal cyclic movement of human arm and resting limb tremor in Parkinson's disease (PD) are associated with the oscillatory neuronal activities in different cerebral networks, which are transmitted to the antagonistic muscles via the same spinal pathway. There are mono-synaptic and multi-synaptic corticospinal pathways for co...

The purpose of this study is to validate a computational model that can be applied to studies of movement control and rehabilitation. A two joint, six muscle, virtual arm (VA) model has been developed in previous work [Song et al. 2008a]. The VA model driven by internal noise of neural control of muscles, i.e. the signal dependent noise (SDN), disp...

This paper describes a Functional Electrical Stimulation (FES) system based on the distributed network structure for rehabilitation of stroke patients. This FES system performs surface stimulation to activate the nerve of paretic muscles for training stroke patients to relearn motor functions. The main components of the networked FES system include...

Electrical stimulation of nerve has been successfully applied to treating patients with lower urinary tract dysfunctions. Stimulation at the level of the sacral nerve roots is the most widely applied technique of neurostimulation. Sacral anterior root stimulation (SARS) with sacral deafferentation has been shown to be very effective in significantl...

The purpose of this study is to investigate plausible central and peripheral coding strategies of joint angle by descending γ_s commands and proprioceptive afferents in humans. Experimental evidence in both human and animal has shown that the firing rate of Ia afferents was linearly correlated to joint angle. Yet, experiments did not eluc...

A closed-loop virtual arm (VA) model has been developed in SIMULINK environment by adding spinal reflex circuits and propriospinal neural networks to the open-loop VA model developed in early study [1]. An improved virtual muscle model (VM4.0) is used to speed up simulation and to generate more precise recruitment of muscle force at low levels of m...

Rolston et al. (2009) [1] designed an easy-to-use, modifiable, and inexpensive system for multi-electrode neural recording and closed-loop stimulation. The system can recover rapidly from stimulation artifacts and allow short-latency action potentials (<1 ms post-stimulus) to be detected. This system, however, uses a desktop computer to perform sys...

A distributed network structure of Functional Electrical Stimulation (DNS-FES) system is proposed in this paper for rehabilitation applications to patients with stroke and spinal cord injury (SCI). The network structure can be used to control both surface and implanted stimulators. The main components of this networked FES system include a master u...

We have improved the stability and computational efficiency of a physiologically realistic, virtual muscle (VM 3.*) model (Cheng et al 2000 J. Neurosci. Methods 101 117-30) by a simpler structure of lumped fiber types and a novel recruitment algorithm. In the new version (VM 4.0), the mathematical equations are reformulated into state-space represe...

An integrated, sensorimotor virtual arm (VA) model has been developed and validated for simulation studies of control of human arm movements. Realistic anatomical features of shoulder, elbow and forearm joints were captured with a graphic modeling environment, SIMM. The model included 15 musculotendon elements acting at the shoulder, elbow and fore...

The question as to how the brain controls voluntary movements of the arm and hand still remains largely unsolved despite much research focused on behavioral studies, neurophysiological investigations, and neuronal modeling in computer science. This is because behavioral studies are usually performed without detailed knowledge of the underlying neur...

We constructed a physiologically realistic model of a lower-limb, mammalian muscle spindle composed of mathematical elements closely related to the anatomical components found in the biological spindle. The spindle model incorporates three nonlinear intrafusal fiber models (bag(1), bag(2), and chain) that contribute variously to action potential ge...

A systems model of spinal neuro-musculo-skeletal system (alpha - gamma model) is developed to investigate the plausible roles of spinal proprioceptive feedback in movement control. The model is composed of a joint, a pair of antagonist muscles, length and velocity feedback from muscle spindle, as well as spinal stretch reflex, reciprocal inhibition...

The spinal sensorimotor control system executes movement instructions from the central controller in the brain that plans the task in terms of global requirements. Spinal circuits serve as a local regulator that tunes the neuromuscular apparatus to an optimal state for task execution. We hypothesize that reach tasks are controlled by a set of feedf...

Good performance in cochlear implant users depends in large part on the ability of a speech processor to effectively decompose speech signals into multiple channels of narrow-band electrical pulses for stimulation of the auditory nerve. Speech processors that extract only envelopes of the narrow-band signals (e.g., the continuous interleaved sampli...

Control of reaching task requires a strategy that takes into account biomechanical couplings in the musculoskeletal system. In a kinematic study, normal subjects were asked to reach to, grasp a cup, and bring it back. It was found that forearm rotation was coordinated in a particular manner with elbow motion in order to keep the cup in a leveled or...

The stability behavior of a multi-joint limb with electrically activated muscles provides important clues for postural control of motor tasks. The stability property of the musculoskeletal system can be characterized with its eigenvalues evaluated at operating postures in the workspace. A planar arm model with shoulder and elbow joints and three pa...

When neuroscientists gather to discuss "Movement and Sensation", they tend to discuss neurons rather than muscles and bones. Neurons may be more interesting, but their roles in motor control depend on the mechanical properties of the system to be controlled. Understanding of those properties has been surprisingly elusive, despite the well-developed...

An integrated neuromusculoskeletal (NMS) modeling tool has been developed to facilitate the study of the control of movement in humans and animals. Blocks representing the skeletal linkage, sensors, muscles, and neural controllers are developed using separate software tools and integrated In the powerful simulation environment of Simulink (Mathwork...